Tool for cutting holes in metal shells.



PATENTED SEPT. 18, 1906.

F. H. N. GERWIG.

TOOL FOR CUTTING HOLES IN METAL SHELLS;

APPLICATION FILED 0CT.28. 1904.

m $7 mq Q7 :5: lllll {:2 w

a m //,Ill\

3 m NH w W iii...

XW/W I PATENTED SEPT. 18, 1906.

F. H. N. GERWIG. TOOL FOR CUTTING HOLES IN METAL SHELLS.

APPLICATION FILED 0OT.28. 1904.

2 SHEETS SHEET 2.

INVEN OR 5 E s S E N n W THE mmms PETERS ca., WASHINGTON, n. c

. my improved tool in position.

UNITED STATES PATENT orrron. FREDERICK H. GERFVEE, OF DUQUESNE, PENNSYLVANIA.

TOOL FOR CUTTING HOLES IN METAL SHELLS.

Specification of Letters Patent.

Application filed October 28, 1904. Serial No. 230,376.

To all whom it may concern:

Be it known that I, FREDERICK H. N. GERWIG, of Duquesne, Allegheny county, Pennsylvania, have invented a new and useful Tool for Cutting Holes in Metal Shells, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a longitudinal section showing Fig. 2 is a side elevation of the same. Fig. 3 is a front elevation, and Fig. 4 is a partial rear elevation.

My invention relates to tools for cutting circular holes through metal shellssuch as the casing of a blast-furnace, a water-tank, gas-tank,standpipe, or a structural column where there is no convenient means for fastening the ordinary ratchet drill, and is particularly adapted for blast-furnace work.

Where a portion of the shell of a blastfurnace becomes hot through the action of hot gases passing through the refractory lining or brickwork, it often becomes necessary to cut a hole through the shell or casing and insert a pipe through which plastic or liquid material is forced in between the shell and the brickwork or lining in order toprevent the shell from becoming so hot as to injure and buckle it.

My invention is designed to provide a simple and effective tool for the cutting of such holes.

In carrying out my invention I first tap a small hole into the shell in the ordinary manner. This small hole can be quickly and easily cut and tapped and into it is screwed the inner screw-threaded end 3 of the stud or bolt 2. This bolt is provided with an angular head 4, by which it may be screwed, and is screw-threaded in its reduced outer portion, as shown at 5. Over this stud is slipped my novel tool, which consists of a cylindrical cutter 6, which is shown as formed at the end portion of a steel cylinder or tool-body 7. This cylinder is provided with a wrench portion 8, and at the rear end of its cylindrical portion is formed the race 9 for a ball-bearing, the other race being formed in a steel ring 10, which is held in place by a brass bushing 11, secured to the cylinder 7 by screws 12.

After this tool is slipped over the stud o1 bolt a feed-wrench 14 is screwed upon the threaded portion 5 of the stud and acts to force the cutter against the shell 15 of the blast-furnace. The hub 16 of this wrench bears directly against the ring 10 on which the tool rotates.

The tool is turned by a large hand-wrench 17, having two arms and a central aperture arranged to fit over the wrench-faces 8 of the tool. This cutter-wrench may be provided with screws 18, which may be forced against the casing after the hole is out.

In using the device the stud is screwed into the hole, the cutter is slippedover it, the feed-Wrench and cutter-wrench applied, and the circular groove thus cut through the shell around the stud.

As soon as the cutting edge of the tool passes through the plate the tool and stud can be pulled out with the plug of metal around the stud, and, if necessary, forced out by the screws 18 on the cutterwrench on each side of the tool. A pipe can then be inserted in the circular hole and expanded therein in the ordinary manner. The hole may also be tapped and the pipe screwed in, if desired, but I find that the eX- panding of the pipe is quicker and easier where time is important.

The advantages of my invention result from the simplicity and ease of applying the tool where the ordinary ratchet-tool cannot be set up. The use of the stud or bolt provides the necessary backing for forcing the cutter against the plate or shell. acts to cut away the metal around the stud, so that when the hole is complete the tool can be pulled away at once.

The tool is applicable wherever it is desired to cut a circular hole in a plate, casing, shell, or column, and many variations may be made in the form and arrangement of the tool and the stud without departing from my invention.

I claim- 1. A tool of the class described comprising a mandrel, a cutter mounted to rotate upon the mandrel as an axis, the mandrel being Patented Se t. 18,1906; I

can be with a screw-threaded end, of a cutting-tool having a hole arranged to fit over the stud and provided with an angular wrench-face, a Wrench fitting on the wrench-face of the tool and having adjustable screws extending through it, and a wrench having a screwthreaded hole engaging the outer screwthreaded end of the stud; substantially as described.

3. A tool of the class described comprising a mandrel having means for connection with the work, a rotary cutter upon the mandrel, and threaded means carried by the tool for engagement with the work to force the tool with the plug cut thereby from thework.

4. A tool of the class described comprising a mandrel having means for connection with the work, a rotary cutter upon the mandrel, a handle carried by the cutter for rotating the same, and an adjustable screw piercing the handle and capable of being engaged with the work to force the tool wit the plug cut thereby from the work.

5. A tool of the class described comprising a mandrel having means for connection with the work, a rotary cutter mounted upon the mandrel, a cap carried by and projecting at the outer end of the cutter and having its outer side open, a bearing member rotatable within the cap concentrically with the mandrel, the bearing being exposed through the open side of the cap, and a feed device mounted upon the outer end portion of the mandrel in frictional engagement with the bearing for moving the cutter endwise upon the mandrel.

6. In a tool of the class described, the combination of a mandrel provided with means for connection with the work, a rotary cutter mounted upon the mandrel and provided with a reduced non-circular portion having an annular shoulder at the rear end of the reduced portion, a-handle provided with a noncircular opening removably receiving the non-circular portion of the cutter, the shoulder of the cutter preventing displacement of the handle rearwardly, and a feed device carried by the rear portion ofthe spindle for feeding the cutter forwardly.

In testimony whereof I have hereunto set my hand.

F. H. N. GERWIG.

Witnesses:

E. P. FAIDLEY, HOWARD L. BLACK. 

